EE WAS ATTEMPTING TO PULL A METAL CHOKER OFF A RIPPER SHANK ON A 854 DOZER WITH A PRY BAR. THE PRY BAR SLIPPED OUT OF THE LOOP WHEN HE WAS APPLYING PRESSURE AND HE ROLLED HIS RIGHT ANKLE OVER AS HE FELL. EE FRACTURED HIS RIGHT ANKLE. HE WAS TRANSPORTED TO THE HOSPITAL AND RECEIVED SURGERY TO REPAIR THE ANKLE.